<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<!--view视图-->
<div id="app">
    <h1 v-if="type==='A'">A</h1>
    <h1 v-else-if="type==='B'">B</h1>
    <h1 v-else-if="type==='D'">D</h1>
    <h1 v-else>C</h1>
</div>


<!--1.导入vue.js-->
<script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
<script>
    var vm= new Vue({
        el: "#app",
        data: {
            type: 'A'
        }
    });
</script>
</body>
</html>